In laser material processing using a powdery additional material, e.g., in deposition laser welding with powder or laser metal deposition (LMD), metal powder is applied onto a substrate through introduction of laser beam energy. It is possible to produce many 2-dimensional and 3-dimensional surfaces or volumes by disposing individual powder paths next to each other and on top of each other to form individual layers and/or layer packages. During deposition laser welding with powder, the quality of the layer can depend on the adjustment of the powder focus with respect to the laser beam and also on the powder quality. In order to obtain high accuracy when processing components in this fashion, and in particular when several layers are formed on top of each other, it is generally desired that the layer characteristics be uniform and reproducible and/or be adjustable during the process.
One way to increase accuracy is to implement process monitoring and control techniques. For example, US 2004/0133298 A1 discloses a method in which several layer properties, such as dimensions, solidification rate, and/or roughness are monitored and, based on those properties, laser power and feed rate can be adjusted. U.S. Pat. No. 6,459,951 B1 discloses a method in which, in addition to laser power and feed rate, the powder application rate can be regulated through the process temperature. This document does not mention adjustment of the powder and laser beam focus with respect to each other or adjustment of the point of impingement of the powder with respect to the laser beam on the workpiece surface.